Abstract: An electric wire connecting device for connecting an electric wire or TV antenna feeder wire to a receptacle or terminals only by the tightening action of the device which passes a blade provided within the connecting device through the insulation cover layer so as to be contacted directly with the conductive wire core made normally of copper wire, so that electrical connection can be obtained. The invention is comprised of: basic body (1) and blade (1a) standing erect from the body, a pair of pressing pieces (1b) bent inwardly at both end edge portions, a pair of anti-motion pieces (1c) bent inwardly at both end edge portions and diverging from said pressing pieces with a predetermined cut out portion therebetween, and a stopper coupling groove (1d) defined by a cutout at a central portion of the rear edge of the body for coupling with a mating protrusion so as not to rotate with screwing of the tightening screw.